At work, we are following this rule for a feature. We have to maintain compatibly for this feature in the next release while working on the functionality that interacts with it.

We don't know how many if any customers actually use it, but if we broke it, someone would complain.

We think we have all the cases covered and that it won't break, but it isn't polished the way it should be. The error messages aren't as great as they could be. But it works. If we have time later, we may come back to it. If a customer files a bug, we will address it then. In a year, it might even be pulled from the product.

For now, we make it usable, but not perfect.